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Prime Vs Prime By Stick Rice & Perry Gartner

Red leads 6away/8away and is on roll.   What is the proper cube action?

Scroll down for the answer and commentary by Stick.




In the actual match, I doubled and my opponent dropped.  As you can see from the Extremegammon Eval below, it is a take.

Here are Stick's comments on this position which I think you will find very insightful relating to similar positions:


This is indeed a take.  There are many details I'd take in to account in this position.  First off, an adage I know to be true is in a prime v. prime position, it's a take.  Now, you have to know where to apply this blanket statement but in general, anything that looks like a somewhat common prime v. prime situation, if you get cubed, you should take.

In the actual position at hand there's more going on of course, but that would still resonate in my mind.  Next I'd look at the race, not because it is a race or that the race may even be important but if it's close or I'm ahead this always argue for a take if you need a tiebreaker.  As you'll note, the race is basically even.

Now on to more important things, like 'how do all of my opponent's upcoming rolls play?'  I go through them individually noting how many immediate bad rolls he has.  In this group I'd place the following [31 43].  I'd move on to the next subset of rolls that aren't his worst but are clearly not good rolls for him (he'd reroll if given the opportunity)  Here I have [61 33 44 64 11]  That's 11 rolls that I view as 'good for me'.  The rest of the rolls do vary in their goodness but when analyzing this position I'd lump them all together as bad for me.

If my opponent doesn't cover the back of his prime or is forced to hit loose I'm definitely in the game.  I can hit back immediately and having the strongest 4pt board I can have a lot of bite in my offensive position.  Even if he does hit loose and I simply come in not hitting I have play from there.  If he doesn't cover the back of the prime I can hop immediately or if unable to hop, perhaps attack his lone back checker buying myself time to escape again while our boards are of equal strength.

I've played this game out many times now, something I suggest you doing if you're interested.  Never did it arise that I needed to slot the bar as you asked from the outset.  You'll either be trying to hit back when hit loose, trying to hop the prime when it wasn't made, or safetying blots hoping that your opponent cracks against your 4 prime or if he hops you send the checker back.  Sometimes he'll cover with the blot from the midpoint (like with 41 or 32) and then you'll hope to roll an ace, get two of his checkers back, and wreck his timing from there.

Another thing of note at the score is that you will be reshipping quickly.  For instance, if he fails to make the prime, you hop out and are missed, this is a perfect opportunity to send it back even though the race will still be even.

Additional comments by Perry Gartner:

  I would extend Stick’s concise and cogent analysis to include what reasonable estimates made OTB  would look like in this position.

                                                                   Wins in 36 games:

Worst numbers- Not making the prime, not hitting, not switching-                                     1-3, 3-4                               = 1.5 games

Numbers not making the  prime,  but hitting or switching-                                            1-1, 1-6, 3-3, 4-4, 4-6, 6-6      = 3.0 games

Numbers hitting on Brown’s mid.-                                                                                 1-4, 1-5, 2-3, 2-4                 = 2.0 games

Numbers that make the 6 prime or hit the outfield blot- 16 remaining                                                                      = 4.0 games

                                                                                                                                                                Total Wins = 10.5 games

 

I would also add :

Notice that brown is one pip up in the race and on roll. An equally timed position would have Brown four down. Therefore Brown with an effective 5 pips lead causes his timing to be slightly worse than White’s. This consideration is compensation for Brown’s stronger prime  where neither side escapes early on, and then White escapes before Brown does. This variation is represented in the group of 16 numbers where I estimated White’s wins at 4.0 games.

Eval:

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